Making your own street gang/slaves its really fun.
As you can see Eric (Nervisfr) doesnt use GS at all and his transformations are great. Use what you are more confortable with, and the end results will be great. The only limit is our imagination. 
you say right Rui.

i'm still not a fan of Green.

With Plastic figurines is more easier because the plastic glue can do the job instead the use of green. Put more glue and some small part of plastic and the glue dissolve the plastic.
Then you get something like Green without the trouble of the Green.
Sometime i use the Pattex putty for cold jonction but i prefer airdrying clay like my copplestone bases.
Plastic is fantastic, but i don't like to paint it...sniff.
Eric